Our optional solar heat rejection system makes 'cool lighting' even cooler.

Heat Rejecting Visualization (Image credit: http://www.nachi.org/low-e-windows.htm)
Sundolier already provides lower heat gain compared to electric lights and even other dayligthting solutions in equally lit spaces.
In many locations extra heat is desireable. But in other places and for certain applications, it is not.  So we offer a high-performance heat rejection system that blocks most of the solar infrared radiation while allowing most of the solar visible light to pass through.


Our specialized glass keeps it cool inside.

Our heat rejecting “hot mirror" is a special type of glass which rejects heat (infrared light) back to the outside while transmitting high-volume, full-spectrum visible light indoors.  The system filters heat by rejecting infrared wavelengths, allowing just the visible part of the solar spectrum to get through.
With an average visible light transmittance of more than 93%, and an average infrared reflectance of more than 95%, this option can nearly eliminate unwanted heating without reducing performance.


  • Thickness: 3.3mm & 1.75mm 
  • Size: Up to 24” diameter 
  • Angle of Incidence: 0º 
  • Average Transmission: 92% 425mm - 700mm 
  • Nominal Transmission: 50% @ 730nm 
  • IR Reflection: 95% 750mm - 1100mm

Maximum performance, all of the time.

Our heat rejection system is one of the most efficient solutions available to stop solar heating. And Sundolier actually helps this technology to perform better.  Standard heat rejecting 'hot glass' operates best when the sun angle is at a zero (0) degree angle of incidence to the glass.  With Sundolier, sunlight is always delivered to the hot-mirror glazing at a zero degree angle of incidence. And because Sundolier tracks the sun and collimates the beam, regardless of time of day or season, our heat rejection system provides the best visible light transmittance with optimal heat rejection available.